public class Test {
    public static void main(String[] args) {

        Teacher liTeacher = new Teacher("李老师");
        Student zhang = new Student("小张");
        Student wang = new Student("小王");


        liTeacher.openCourse("Java基础", 2);
        liTeacher.openCourse("大学英语", 3);
        liTeacher.showCourses();


        Course java = liTeacher.myCourses.get(0);
        zhang.selectCourse(java);
        wang.selectCourse(java);
        zhang.selectCourse(java);
        zhang.showCourses();
        wang.showCourses();


        zhang.dropCourse(java);
        zhang.showCourses();
        liTeacher.showCourses();
    }
}